DIY automotive a/c tools?

[JD3020]

At the moment i've got 2 trucks that need the A/C system put back together and cleaned/charged, as well as some other vehicles and equipment that need checked and re-charged before summer hits. Used to have a guy that did all our A/C work cheap and did great work, but he retired last year and moved away. I haven't tried talking to another shop but at this point i might as well look into doing it myself. I've seen some small A/C machines list for $16-1800 but thats out of my budget for something that won't get used a lot.

So has anybody in here rigged up something is or can you point me in the direction to figure out whats needed and how to do it?

 

[ckeboss]

They sell small evacuation machines. https://www.amazon.com/gp/aw/d/B00N...SX236_SY340_QL65&keywords=ac+recovery+machine

 

[ike]

Most auto parts stores rent the vacuum pump, i think some rent manifold gauges. I did a DIY compressor replacement last summer. I purchased:

These gauges, with a coupon they were about the same price as some on Amazon, and I picked them up down the street
https://shop.advanceautoparts.com/p/interdynamics-professional-manifold-gauge-hose-set-429/99981458-P?searchTerm=manifold+gauges

I got this vacuum pump
https://www.amazon.com/gp/product/B012CFTYX4/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I got this flush kit
https://www.amazon.com/gp/product/B0002JMEQW/ref=od_aui_detailpages00?ie=UTF8&psc=1

I don't think a recovery system is really something people buy for an occasional DIY job.

 

[Wamsutta]

I don't think a recovery system is really something people buy for an occasional DIY job.

But you still have to hook the vacuum pump up to some kind of a tank so you can pull a vacuum don't you?

 

[jonesg]

But you still have to hook the vacuum pump up to some kind of a tank so you can pull a vacuum don't you?

No, vacuum is generated, not stored.

 

[cvairwerks]

Might need to do some checking, R-134A is supposed to be regulated and have purchase restrictions under both Sections 608 and 609 of the EPA codes as of Jan 1 of this year. Appears that you must now have the cert to buy it.

 

[Wamsutta]

Might need to do some checking, R-134A is supposed to be regulated and have purchase restrictions under both Sections 608 and 609 of the EPA codes as of Jan 1 of this year. Appears that you must now have the cert to buy it.

You had me scared so I checked Walmart's site. It's still being stocked locally.

 

[cvairwerks]

A little more digging shows that 2 pound or smaller cans with either: system unique fittings and/or self sealing valves and were manufactured after 1 Jan 18, can be sold without a license. Wouldn’t be suprised to see that get tightened up in the near future since Europe has now banned use of R-134A in the near future.

 

[JABgj]

I picked up an older Robinair pump from CL for 25 bucks and a set of gauges on Amazon for less than 40. I will probably not use these tools more than a dozen times in my lifetime, but it will let me do work that will save hundreds.

 

[idickers]

Automotive a/c is entirely do-able as a DIYer. I had been frustrated by lack of decent work on my car a few years ago and happened to have just read Rob Siegels' "Memoirs of a Hack Mechanic." In addition to being highly entertaining, he has a chapter on automotive a/c that was inspiring (he's got an entire book on the subject coming out soon).

Based on Rob's book and a little online digging, I bought a set of Mastercool 89661 gauges, a Robinaire 15500 vacuum pump, and a tank of nitrogen. When I have work to do I have the system evacuated by a shop (usually about $25), and then fill the system with nitrogen to test for leaks, using soapy water to find the leak. After making sure it holds pressure I vacuum the system with my pump, usually for 3-4 hr then let it sit overnight. If it holds vacuum overnight I'm good to go, and add r134a from cans I buy at walmart. The trick is getting a chart for your car that plots temp and humidity vs high and low side pressure.

This is actually very straightforward. I've retrofitted my '91 BMW 318is to 134a, and kept three of my own other cars running with 134a, and picked up some nice wine and scotch charging and trouble-shooting friends systems.

 

[JABgj]

Automotive a/c is entirely do-able as a DIYer. I had been frustrated by lack of decent work on my car a few years ago and happened to have just read Rob Siegels' "Memoirs of a Hack Mechanic." In addition to being highly entertaining, he has a chapter on automotive a/c that was inspiring (he's got an entire book on the subject coming out soon).

Based on Rob's book and a little online digging, I bought a set of Mastercool 89661 gauges, a Robinaire 15500 vacuum pump, and a tank of nitrogen. When I have work to do I have the system evacuated by a shop (usually about $25), and then fill the system with nitrogen to test for leaks, using soapy water to find the leak. After making sure it holds pressure I vacuum the system with my pump, usually for 3-4 hr then let it sit overnight. If it holds vacuum overnight I'm good to go, and add r134a from cans I buy at walmart. The trick is getting a chart for your car that plots temp and humidity vs high and low side pressure.

This is actually very straightforward. I've retrofitted my '91 BMW 318is to 134a, and kept three of my own other cars running with 134a, and picked up some nice wine and scotch charging and trouble-shooting friends systems.

Can you elaborate on using the nitrogen at all? I was wondering how to pressure test a system. Could not figure out how to make a soap bubble under vacuum.

 

[idickers]

I got a tank of nitrogen from my local welding shop. Connect the tank up to the manifold, set the tank gauge to 125 lb, and fill up the system. If it holds pressure on the a/c gauge set, close the valve to the nitrogen tank and let it sit for a couple of hours. If you have a big leak you'll hear it, small leaks can be found with soapy water, or Big Blu leak detector. I try not to use the fluorescent dye just because it makes a mess. After I'm comfortable that there are no leaks I evacuate the system and then charge.

 

[HaroRider]

How are you guys recovering the refrigerant?

 

[WhiffySpark]

How are you guys recovering the refrigerant?

They’re not. They accidentally remove the valve core

 

[idickers]

They’re not. They accidentally remove the valve core

Or you can pay a shop to evacuate the old refrigerant for you, and drive home to do the actual repairs yourself.

 

[ike]

I called around to many places and only found one in my city willing to evacuate the system for a reasonable price. Most quoted full price for an a/c evac and refill, despite the refill part not happening. Many of the estimates i got for the service were absurd, basically a we don't want to do that price. Other places I called seemed baffled that someone would want just an evacuation, so apparently it's not a common request. I assume that most people just bleed it out into the atmosphere. For something where people are requested to do the ethical thing and have it properly recovered, it was a very challenging thing to find someone willing to help me accomplish that. I read many places where people talked about local shops doing it for a small fee, but i certainly didn't find that to be the case in my city.

 

[engineer2]

If looking for a leak, another way to do it is to avacuate as best yo can and charge up with a little 134a (or whatever) and use an electronic leak detector. I have a Tif 8800A combustible gas dectector for larger leaks and a used H10 (sold under various brand names) for little leaks. Sad news when it's an evaporator leak.

Once you repair the leak and change whatever needs changing (receiver dryer), I like to pump the system down at least several hours or overnight. I use an old Supco VG-60 gauge to monitor vacuum. If you get down to the micron range pretty quck, you can be assured don't have a major leak.

Keep in mind the oil in your vacuum pump should be changed on a regular basis.

 

[engineer2]

...seemed baffled that someone would want just an evacuation,

DIYers are a dwindling bunch around here. Most places will want to put the 134a back in as long as eveything is hooked up and nothing leaks. If they can put the right amount in by weight, Bonus!

 

[Milton Shaw]

On some cars is the compressor craps out you need to change the condenser coil too. Some cars are multi path condenser where you cannot flush out the trash from the coil as those tube are stopped up and bypassing to the other paths when you flush. On the issue of recovery, most of the time the A/C is not working because its very low on R134, its already leaked out so nothing to recover. On leak testing use the can right side up and charge with vapor pressure to get R134 in the system to leak test with a sniffer. Then you have only added like 1/2 to ounce of R134 and there is not enough in there to recover.

 

[JABgj]

What I end up working on usually has leaked out all of the refrigerant by the time I get to repair it. I would contact a local shop to evac if needed.

 

[kythri]

So where's the cheapest place to buy a 30lb cylinder of R-134a ?

 

[engineer2]

I've been buying the 12 oz cans at Menards for $4 or so. Sams Club used to sell 30 lb cylinders, but haven't seen them in a few years. Sams sells the 12 oz for $4.50 ea. I would check Amazon for 30 lbs.

 

[Wamsutta]

No, vacuum is generated, not stored.

That makes sense. Thanks for the lesson.

 

[dclassical]

So where's the cheapest place to buy a 30lb cylinder of R-134a ?

I bought mine in 2015 at Sam's Club, $75 I believe. I have not kept up with prices.

But I do believe you do need a 609 certification. It is an online, open book test for $20. I may take it, I took the 608 years ago and it was not too hard. Do some reading, understand how the systems work and take the test.

 

[kythri]

I got my 609 about 15-20 years ago so I could pick up some R-12, so I'm good there. Just figured I'd pick up a cylinder of R-134a before the collective push to get rid of it goes crazy.

 

[akalian]

I got my 609 about 15-20 years ago so I could pick up some R-12, so I'm good there. Just figured I'd pick up a cylinder of R-134a before the collective push to get rid of it goes crazy.

If you need it you would be wise to stock up. The new systems come with YF1234 and it is incompatable with R134a and it costs a lot more as well. It's also incompatable with the current machines that shops are now using, so they will have to buy all new equipment, and you are going to help pay for that with increased rates.

Additionally, it's flammable and Mercedes is outfitting some of their cars with an Argon Fire Supression system to put out any fires that might start after a collision. I'm sure that will cost a pretty penny.

In the meantime, Daimler, which had charged that the alternative refrigerant R-1234yf posed potential fire safety dangers, has finally agreed to use R-1234yf systems in its Mercedes vehicles for markets where the refrigerant either is mandated or is effectively pressed for by regulatory bodies (as in the U.S.). However, no rollout schedule has been announced. Daimler will add an underhood "fire extinguisher"—an argon gas canister with spray lines directed at all parts that its engineers say might become hot enough for a leaking refrigerant to ignite.

http://articles.sae.org/14631/

For example, here's a 160 oz or the equivalent of 13-12oz cans of the stuff. At $5.00 a can for R134a that comes to $65 so the new YF1234 stuff works out to something on the order of 15 times more expensive.

https://www.oreillyauto.com/detail/...rigerant-160-ounce-refrigerant/1234yf/4321745

It's ironic indeed that they named it what they did. YF as in Your're F*cked

It's supposed to become mandated in 2021 models, and expect a lot of people to be shocked on what an A/C service will cost them.

And once the shops all convert to the new equipment, trying to get your R134a system serviced will become more expensive as well. Unless all the A/C shops decide to keep duplicate systems.

This paragraph caught my eye from this article:
http://www.underhoodservice.com/hfo-1234yf-whats-required/

Don’t worry, R-12 and R-134a will not be phased out, but they will be regulated and taxed heavily.

This is good news for shops because the days of DIY A/C repair in a can are numbered.


.

 

[JD3020]

Leave it to the govt to fix an "issue" with a tax.


As for my vehicles one was professionally evacuated when i did an engine swap, the other was evacuated by a lovely 4 legged animal that wanted to play frogger with our truck the day after we bought it. Both systems have been open for 3-4 years so i'll be getting all new Ford/Motorcraft parts to go on. Going to replace everything except the evaporator core. But i would love to get a machine to evacuate a system when i do an engine swap or something where the a/c **** is in the way. I had to swap out a V10 in a F-350 last year and we didn't want to spend the time and money to deal with the A/C so i had to hang the condenser over the fender and work around it.

 

[engineer2]

Additionally, it's flammable

Too bad propane is so flammable. It's an excellent refrigerant.

 

[kythri]

This paragraph caught my eye from this article:
http://www.underhoodservice.com/hfo-1234yf-whats-required/

Don’t worry, R-12 and R-134a will not be phased out, but they will be regulated and taxed heavily.

This is good news for shops because the days of DIY A/C repair in a can are numbered.

I know you're quoting an article, but didn't R-12 production cease like 20 some years ago?

 

[6PTsocket]

No, vacuum is generated, not stored.

I think the OP was talking about the vacuum pump pulling out refrigerant and oil. I think there is a little confusion between a vacuum pump and a recovery system.

Sent from my SM-G900V using Tapatalk

 

[akalian]

I know you're quoting an article, but didn't R-12 production cease like 20 some years ago?

It was "officially" phased out in the early 1990's but it's still in wide use today. When I had my A/C system charged in my house, it used R-12, and the A/C tech had a 30lb tank of it. They wanted to convert the entire system to R410 or some such, and I told the tech to just fill it up with R-12.

You can still buy it on eBay as well, but there are lots of fakes.
Watch out for the "R-12 Compatable" listings.
https://www.ebay.com/sch/i.html?_fr...TR12.TRC2.A0.H0.Xr-12.TRS0&_nkw=r-12&_sacat=0

Any A/C shop should have R-12 readily available.

.

 

[engineer2]

Found this:
"India, being allowed to produce CFC-12 until 2010 and HCFC-22 until 2040 as per the Montreal Protocol regulations."

Looks like anything available now is reclaimed R12, or leftover new cans for abour $30-$35 ea.

 

[Junkman]

Too bad propane is so flammable. It's an excellent refrigerant.

Last December I received a replacement glass door commercial freezer from a manufacturing company in Canada. It is charged with propane, and I was told that it holds about 6 ounces. Somehow, they got the efficiency up, and the size of the system down. It works as well as the unit that it replaced.

I know you're quoting an article, but didn't R-12 production cease like 20 some years ago?

Yes, production ceased a long time ago, however, even though they ceased production, there is still a very large supply available. The price fluctuates widely, depending on season, and demand. I was buying 12 oz. cans at swap meets for $10. I also picked up some partial 30 pound cylinders. The downside to the 12 oz. containers, is that when you put a tap on the top, there is a good chance that the internal seal is going to fail, and you will loose the refrigerant to the atmosphere. I have resolved this issue by using a side tap on the cans. It actually works better and faster than using the can top tap.

If I have to evacuate a system, I will drive the car to a local salvage yard, and they will evacuate the system for a few dollars. Just have to schedule it when they are not busy. They have machines for both R12 and R134.

New EPA Rules can be found here......

 

[pilotmotor]

You can make a vacuum pump with the compressor of any old a/c unit , water cooler , dehumidifier , fridge ect... as long as it still works. just cut it out of the doner and braze on what ever fittings you want. For car a/c evacuation thats all you will need. I never tried it but you could probably use the engine vacuum to evacuate also , although not a great idea, the under hood heat would help also !!

 

[inline five]

To these guys pulling a vacuum for hours....guys...totally not needed for automotive A/C.

Techs working larger several ton systems might do it for 30-45 mins to achieve sub 500 microns....

The gauges from HF work great, as does the cheapie vacuum pump.

Buy the $4 cans at Walmart, use a kitchen scale to weigh in the charge, this stuff isn't rocket science. Even if you are just close you'll be fine. Been there done that got the T-shirt and A/C in my cars works great.

 

[SouthLake]

To these guys pulling a vacuum for hours....guys...totally not needed for automotive A/C.

Techs working larger several ton systems might do it for 30-45 mins to achieve sub 500 microns....

The gauges from HF work great, as does the cheapie vacuum pump.

Buy the $4 cans at Walmart, use a kitchen scale to weigh in the charge, this stuff isn't rocket science. Even if you are just close you'll be fine. Been there done that got the T-shirt and A/C in my cars works great.

this ^^^^

 

[royesses]

Sam's still sells r-134a in 30lb cylinders and 1lb cans. Last summer I purchased 2 cylinders at $66.00 each. Also purchased 3 case of cans $33.00 a case.


Roy